Oxyalkylated isocyanuric acid



. 3,265,694 OXYALKYLATED ISOCYANURKC ACID Wilhelm E. Walles, Midland,and James J. Davies, Mount Pleasant, Mich, assignors to The Dow ChemicalCompany, a corporation of Michigan No Drawing. Original application July25, 1960, Ser. No. 44,893. Divided and this application Oct. 14, 1963,Ser. No. 334,681

Claims. (Cl. 260-248) This application is a division of copendingapplication, Serial No. 44,893, filed July 25, 1960.

This invention relates to the oxyalkylation of isocyanuric acid. i

It is known that ethylene oxide can be condensed with cyanuric acid inthe presence of a basic catalyst to produce 1,3,5-tris(Z-hydroxyethyl)isocyanu-rate.

According to the invention alkylene oxides are condensed with acidiccatalyst to produce 1,3,5-tris(2-hydroxyvalkyl) isocyanurates. Thisreaction can be represented as follows:

wherein R and R are hydrogen or lower alkyl radicals and R" is a loweralkyl or a phenyl radical.

Among the alkylene oxides useful in the first step of the process arepropylene oxide, 1,2- and 2,3-butylene oxides, isobutylene oxide,styrene oxide and the like. It is preferred to use the stoichiometricamount of oxide; i.e., three moles per mole of isocyanuric acid. Lessyields a mixture of partially oxyalkylated products While more favorsthe formation of polyoxyalkylene chains.

Suitable acid catalysts for the process include various strong mineralacids, such as sulfuric acid alkali metal bisulfatcs, sulfonic acids,hydrochloric acid, hydrobromic acid, phosphoric acid, strong acidion-cxchange resins, and the like. Only a small amount is required,suitable amounts being of the order of 0.1 to 2%, by weight, based onthe combined reactants.

Since the reaction of alkylene oxides with cyanuric acid is exothermic,it is preferable, though not essential,

In each of three experiments, 754 g. of cyanuric acid were dissolved in4 liters of dimethyl formamide. The

3,265,694 Patented August 9, 1966 solution was placed in aclosed reactorand heated to 160 C., after which 945 g. of propylene oxide were slowlypumped in while the temperature was maintained constant. Stirring andheating at 160 were continued for 2 hours, after which the reactor wascooled and the solvent was removed by vacuum distillation. The residuewas subjected to high-vacuum distillation, the 1,3,5-tris(2-hydroxypropyl) isocyanurate, if any, distilled at 199" C. (0.6mm.) while the final residue was essentially cyanuric acid. The reactionmixtures could also be analyzed by infra-red analysis.

The only variable in the above three experiments was the catalyst used,the results being as follows:

Example Catalyst Yield of tris-hydroxypropyl isocyunurate 1A H2804, 1%1B. Nu0lI,0.S% 0 1C None- 35 Example 2 Into a pressure reactor was put129.1 g. (1 mole) of cyanuric acid, 174.6 g. (3 moles) of propyleneoxide, 600 ml. of dimethyl formamide-and 2 ml. of sulfuric acid. Thevessel was then heated at 170 C. for 30 min., during which time thecharge was continuously agitated. "The reactor was then cooled and thesolvent removed by distillation at 1 mm. pressure. The residue was avery viscous liquid and was shown by infra-red analysis to consistessentially of l,3,5-tris(Z-hydroxypropyl) isocyanurate.

The 1,3,5-tris(Z-hydroxyalkyl) isocyanurates of the invention aretypical polyols in that they are viscous, neutral liquids havingconsiderable affinity for water. They are useful for most of thepurposes for which other polyols are used; e.g., they are readilyesterified with mono carboxylic acids to form monomeric esters useful asplasticizers for cellulosic plastics such as ethyl cellulose, celluloseesters and hydroxyalkyl cellulose. They are also readily esterified withdiccarboxylic acids to form polyesters resins useful as surface coatingsand molding plastics.

By using one of the butylene oxides or styrene oxide instead of thepropylene oxide used in the above examples, there is obtained thecorresponding ethyl, dimethylor phenyl-substituted Z-hydroxyethylisocyanurate.

By lower alkyl as used herein we mean alkyl radicals containing up toabout [our carbon atoms.

We claim:

1. The process for oxyalkylating cyanuric acid comprising reacting bycontacting cyanuric acid with at least three molecular equivalents of analkylene oxide in the presence of an acid catalyst and at a temperatureof about to 200 C.

2. The process defined in claim 1 wherein the alkylene oxide ispropylene oxide.

3. The process defined in claim 1 wherein the catalyst is sulfuric acid.

4'. The process as defined in claim 1 wherein the reaction is conductedin an inert solvent.

5. The process for making 1,3,5-tris(Z-hydroxypropyl) isocyanuratecomprising reacting by contacting cyanuric 3 acid with at least 3molecular equivalents of propylene oxide in the presence of a catalyticamount of sulfuric acid and at a temperature of about 150 to 200 C.

References Cited by the Examiner UNITED STATES PATENTS 4 OTHERREFERENCES Eastham et al.: Canadian Jour. Chem, vol. 29, (1951), pp.575-84.

Yurev et al.: Refenat. Zhun, Khim (1953), No. 8488.

WALTER A. MODANCE, Primary Examiner. JOHN M. FORD, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3, 265,694 August 9, 196

Wilhelm E. Walles It is hereby certified that error appears in the abovenumbered patent requiring correction and that the said Letters Patentshould read as corrected below.

In the heading to the printed specification, lines 3 and 4, strike out"and James J. Davies, Mount Pleasant, Mich.,

assignors" and insert instead Mich. assignor Signed and sealed this 21stday of November 1967.

(SEAL) Attest:

EDWARD J. BRENNER Edward M. Fletcher, Jr.

Attesting Officer Commissioner of Patents

1. THE PROCESS FOR OXYALKYLATING CYANURIC ACID COMPRISING REACTIN BYCONTACTING CYANURIC ACID WITH AT LEAST THREE MOLECULAR EQUIVALENTS OF ANALKYLENE OXIDE IN THE PRESENCE OF AN ACID CATALYST AND AT A TEMPERATUREOF ABOUT 150* TO 200*C.